Rotor blades in fibre-reinforced composite design, in particular also fenestron blades, have already been used for about 30 years. In the helicopter “Dauphin N4” made by the applicant, a fenestron blade in RTM construction was used in which a separate tension-torque-transmission element made of metal was connected in a control tube by means of a bolt attachment. The control tube was tied in a single piece to the rotor blade and was also constructed in a fibre-reinforced composite design. However, due to the necessity of applying many individual fibre layers, production of this fenestron blade was involved and very cost-intensive. Added to this cost disadvantage was a comparatively short service life.